Patents by Inventor Fumio Murai

Fumio Murai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5250812
    Abstract: An electron beam lithography apparatus is disclosed which has an aperture plate provided with an aperture including an array of repeated unit patterns and an ordinary aperture of a rectangular shape. A region free of the influence of a proximity effect is delineated using the former aperture, and a region affected by the proximity effect is delineated using the latter aperture. The number of repeated unit patterns included in the former aperture is determined considering the number of repeated unit patterns included in a pattern array to be delineated on a substrate. Thereby, the number of electron beam shots is reduced. A plurality of apertures having slightly different aperture widths may be provided for always keeping a pattern line width constant.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: October 5, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Murai, Shinji Okazaki, Haruo Yoda, Yukinobu Shibata, Akira Tsukizoe
  • Patent number: 5149975
    Abstract: The present application relates to a method and an apparatus for forming a pattern, in which a plane on which a pattern on a sample is traced is decomposed into predetermined partial regions; the pattern density in each of the partial regions is stored in data storing means as pattern density map data; and the irradiation energy amount of a charged particle beam is corrected on the basis of the pattern density map data to correct shortage and excess in the exposure dose due to roughness and fineness of the the pattern, i.e. the proximity effect. Further, the present application relates to a method and an apparatus for forming a pattern, in which when one or a plurality of layers located under the layer on which the pattern should be formed have patterns, influences of the underlayers on the proximity effect are taken into account.
    Type: Grant
    Filed: January 29, 1991
    Date of Patent: September 22, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Haruo Yoda, Fumio Murai
  • Patent number: 5061599
    Abstract: A radiation-sensitive material comprising a polyacid composed of tungsten and niobium, titanium and/or tantalum. A uniform film can be formed by an easy spin coating method. The polyacid has a radiation sensitivity higher than that of a polyacid comprising only tungsten.
    Type: Grant
    Filed: January 5, 1990
    Date of Patent: October 29, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuichi Kudo, Akira Ishikawa, Hiroshi Okamoto, Katsuki Miyauchi, Takao Iwayanagi, Fumio Murai, Shinji Okazaki
  • Patent number: 4983532
    Abstract: Microfabrication and large scale integration of a device can be realized by using a planar heterojunction bipolar transistor formed by a process comprising successively growing semiconductor layers serving as a subcollector, a collector, a base, and an emitter, respectively, through epitaxial growth on a compound semiconductor substrate in such a manner that at least one of the emitter junction and collector junction is a heterojunction, wherein a collector drawing-out metal layer is formed by the selective CVD method.
    Type: Grant
    Filed: December 20, 1988
    Date of Patent: January 8, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Mitani, Tomonori Tanoue, Chushirou Kusano, Susumu Takahashi, Masayoshi Saito, Hiroshi Miyazaki, Fumio Murai
  • Patent number: 4983864
    Abstract: An electron beam drawing apparatus having a grounded conductor for a screening operation in the neighborhood of a detection surface of a detector to detect a reflected electrons obtained by irradiating an electron onto a specimen and a secondary electron generated through the electron irradiation. The conductor has openings to pass therethrough the reflected electron and the secondary electron. As a result, the electric charge accumulated on an organic substance fixed onto the front surface of the detector through the electron irradiation is prevented from exerting an influence on the drawing electron beam.
    Type: Grant
    Filed: March 27, 1989
    Date of Patent: January 8, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Murai, Shinji Okazaki
  • Patent number: 4403151
    Abstract: Desired portions of the positive-type photoresist film are irradiated with an electron beam, and regions including at least the regions irradiated with the electron beam are further irradiated with ultraviolet light, followed by developing.The photosensitive radicals are destroyed in the regions which are irradiated with the electron beam. Therefore, the solubility of the photoresist film is not increased even when it is irradiated with ultraviolet light, and resist patterns are formed by developing.
    Type: Grant
    Filed: April 2, 1981
    Date of Patent: September 6, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Kozo Mochiji, Yozi Maruyama, Shinji Okazaki, Fumio Murai
  • Patent number: 4315984
    Abstract: That region of a resist film in which a contact is to be formed and that region thereof in which an interconnection is to be formed are respectively irradiated with an electron beam in a dose substantially equal to an optimum dose of the resist film and in a dose less than the optimum dose. Thereafter, the resist film is developed.By performing dry etching, an opening extending to a substrate is provided in the region in which the contact is to be formed, and the surface of an insulating film overlying the substrate is exposed in the region in which the interconnection is to be formed.After depositing a conductive metal film on the whole surface the remaining resist film is removed together with the metal film deposited thereon, whereby the contact and the interconnection are formed.
    Type: Grant
    Filed: August 11, 1980
    Date of Patent: February 16, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Shinji Okazaki, Kozo Mochiji, Susumu Takahashi, Fumio Murai